Trephine.



No. 65!,921. Patented June I9, won.

I A..DE VILBISS TBEPHINE.

(Application filed In. 8, 1900.)

(No Model.)

UNITED STATES PATENT OFFI E.

ALLEN DE v1LB1ss,f OF TOLEDO, 01-110.

TREPHINE.

SPECIFICATION forming part of Letters Patent No. 651,921, dated June 19, 1900.

Application filed March 8, 1900. Serial No. 7,842. No model.)

especially to that class of tools used-therein known as trephines, and the object of the same is to improve the construction of a tool of this character.

' To'this end the invention consists in supporting the centering-point loosely and removably, so that it can be held temporarily in place by the operators finger; and the in vention further consists in details of construction, which will appear in the following specification, and all of which are shown in the drawings, wherein Figure 1 is a front elevation of this device in use, with the operators hand in dotted lines. Fig. 2 is a vertical'section through the stem and point. Fig. 3 is an enlarged perspective detail of the lower end of the tool and of the point removed therefrom.

In devices of this character or for analogous use it is common to make the centeringpoint movable within the tubular head. A point is employed with a hollow anger in order that the teeth of the annular active face of the latter will work continually around the same ring until it has penetrated to sufficient depth to form a hole, or at least a cavity, within which the radial flutes will work, after which the tool will center itself, and the center is not further useful. In ordinary instances the point at this time may remain in place and continue to do its work, or it may be moved upward, or it may be permitted to move automatically upward, as by compressing a spring; but in using a trephine care must be taken that the button being bored out of the skull is not pushed through the same after it becomes detached, for otherwise serious results might ensue. My present invention is designed to permit this work to be done in the most eifectual manner and by the very simplest means, and in carrying out the invention I have in mind the desirabilityof using few parts for the sake of cheap! ness of manufacture and cleanliness in use and of so shaping those parts as to lengthen the life of the tool and permit it to be sharpened when required.

Referring to the said drawings, 1 is a stem having at its upper end a handle 2 and at its lower end a head 3. The latter is preferably conical in contour and is hollow, with its bore cylindrical. On its lower end it has an annular series of teeth 4, serving in use as a hollow anger, and on its outer face it has radial teeth or flutes 5, serving in use as a reamer to enlarge the hole made by the teeth 41. The body of the stern above the head 3' is cut away or halved, as at 6, so as to expose the bore 7, which is continued upward in a groove in the half remaining opposite this cut-away portion and preferably has a flat shoulder 8 at its upper end. The material of the remaining half of the stem continues alongside the bore, and above the shoulder 8 is a face 9, flat for a distance and then curved, so that the material grows thicker until it merges into the stem 1. The button is cut by the teeth 4 and may pass up the bore 7 and drop out its open side above the head. In boring through thin material, such as the human skull, after the button has been taken out the hole may be enlarged by continuing the operation, which brings the flutes 5 into play. a

The numeral 10 designates the body of the center, which is cylindrical and of a size to fit loosely within the bore 7. Although its upper end may be of any desired shape, I preferably form it with a shoulder 11, whose flat upper face is adapted to rest against the shoulder 8 at the upper end of the bore and whose upright face forms, with the remaining portion of the body, a lip 12, that passes over and rests upon the face 9. Below this lip the cylindrical body of the center is cut away or formed with a slight depression 13, shaped to receive the tip of the operators forefinger, as indicated in Fig. 1, and located so that it will be exposed when the center is in place. The point 14 at the lower end of the center may be of any suitable shape; but by preference I grind the cylindrical body on three or more flat sides converging to the axial line, the

reason for thisbeing that it is, ordinarily easier w grind flat faces than those of other shape. tremity of the point to the flat face of the shoulder-11 is a trifle greater than from the tips of the teeth 4 to the flatface of the shoulder 8, whereby the point 14' protrudes normally slightly beyond the active end of the head.

The parts are preferably of met-a1, with the The length of the center from the ex eral opening; of'a center fitting loosely and 'removably insaid bore and having a shoulder resting against said flat upper end when its point protrudesslightl-y beyond the head, as and for the purpose set forth. I

2. In a trephine,.the combination witha tubular head provided exteriorly with cuttingteeth, and a stem secured to the head and :halved above it so that the bore extends from the head upward along the stem, is open at working surfaces or portions thereof tempered, and the precise-details of construction are not material, except as hereinafter specified.

In operation the center is inserted and the tool is grasped, as seen in Fig. 1, with the forefingerresting in the depression 13 tohold the'center from falling out. The latter is inserted in the skull and pressed or twisted thereintountil the end'teeth 4 begin to work. Meanwhile rotation of the point is prevented by the fact that the'lip l2 lies on the fiat portion of the face 9, and of course the center cannotbecome displaced. The tool is rotated to: the right, assuming that the teeth-4 face in that direction, until a shallow ring has been formed. Then the tool is withdrawn and the finger removed, which allows the center to fall out. with the teeth 4 within the ring in the skull, and the operation is repeated until the latter is perforated, the button passing upward into the' bore 7. The'tool may be then either further rotated to enlarge the hole radially by means of the flutes 5, in which case the button-will remain within the bore, or the tool canbe removed and the button knocked or The which employ a permanent center or one actuated by a spring is that before complete. perforation is effected and the button has been formed the point has been entirely removed, thus not only leaving a free passage forthe button, but also avoiding every tendenc'y of the button to thepa-tients skull,

What is claimed as new is- 1. In a'trephine, the combination with a tubular head provided exteriorly with cuttingteeth, and a stem vsecured to the head, the bore of the'latter extending upward into the 3 stem and having a flat upper end and a lat- The tool is immediately replaced pass or be pushed within 1 .scribed my signature this the 6th day of one side, and has a flat shoulder at its upper end above which the stem has a face; of a center fitting loosely and removably in said bore and having a shoulder and lip at its upper end, the point at its lower end projecting beyondsaid head when the'two shoulders engage and the lip liesupon said face, as and for the purpose sethforth.

3. In a trephine, the combination with atubular head provided exteriorly with cuttingteeth, and a stem secured to the head and halved above it so that the bore extends from the head upward along the stem, is open at one' side, and has a flat shoulder at itsupper end; of a center fitting: loosely in said bore, and having a shoulder at its upper end and a depression in one side of its body, the point at its lower end projecting beyond said head when the two shoulders engage, as and for the purpose'set'forth.

4C. In a trephine, the combination with a tubular head provided exteriorly with cuttingteeth, and a stem secured to the head and halved above it so that the bore extends from the head upward along the stem,is open at one side, and has a flat shoulder'at its upper end above which the stem has-a face flat for a'distance and then curvedoutward into the stem-body; of a center fitting looselyin-said bore and having a shoulder and lip at its upper end and a depression in one side of. its body, the pointat'its lower end projecting beyond said head when the two should'ersengage and the lip lies upon said' face, as and 'for the-pu-rpose-set forth.

In testimony whereof I have hereunto sub- March, A. D; 1900.

ALLEN 'DE VILBISS.

Witnesses J. T. GREER,

H. T. GREER. 

